1. Technical Field
Example embodiments relate to an insulator composition, an insulating layer including the composition, and a transistor including the same.
2. Description of the Related Art
A thin film transistor (TFT) has been used as a switching device and a driving device for pixels in a flat panel display (e.g., liquid crystal display (LCD), electroluminescence display (ELD)). A TFT may also be applied to a plastic chip so as to function as a smart card or an inventory tag.
A conventional TFT may include a source area and a drain area doped with an increased concentration of impurities. A semiconductor layer having a channel area may be formed between the source and drain areas. A gate electrode may be disposed in an area which corresponds to the channel area while being insulated from the semiconductor layer. A source electrode and a drain electrode may contact the source area and the drain area, respectively.
A conventional TFT channel layer was previously made of an inorganic semiconductor material (e.g., silicon (Si)). However, an inorganic-based material involves a higher temperature vacuum process, thus increasing costs. As a result, the inorganic-based material was replaced with an organic-based semiconductor material. The use of an organic-based semiconductor material also enables the enlargement, cost-reduction, and softening of display devices. Accordingly, there has been increased research regarding an organic thin film transistor (OTFT) using an organic layer as a semiconductor layer.
A conventional OTFT may have a thin film as an insulating layer. The thin film may be formed with a relatively inexpensive solution procedure (e.g., spin coating). However, trap charges may occur at an interface of the thin film because of the intrinsic characteristics of an organic-based material. Additionally, hysteresis may be caused by polarization resulting from external moisture along a sweep direction of the gate voltage. For example, when applying a voltage to a gate electrode, the magnitude of the current between the source electrode and the drain electrode may correspond to the magnitude of the applied voltage. However, the magnitude of the current in a conventional OTFT may not be homogeneously maintained because of hysteresis.
Furthermore, conventional organic insulator compositions used for the gate insulating layer have relatively poor resistance to etchants, photoresist strippers, and other chemicals used in the fabrication process, thus rendering it difficult to maintain the original properties of the gate insulating layer.